Widely used in recent years is a sealing/pump-up device (hereafter simply referred to as a “sealing device”) for a pneumatic tire (hereafter simply referred to as a “tire”) that repairs the tire with sealant and pumps it up to predetermined reference internal pressure without replacing the tire and a wheel when the tire gets punctured.
As the above sealing device, there is a sealing device having a liquid agent container for containing liquid sealant and an injection unit mounted with the liquid agent container, for example. In this sealing device, an air supply path that may be connected to an air supply source such as an air compressor and a gas-liquid supply path that may be connected to a pneumatic tire to be sealed communicate with each other through a space inside the liquid agent container and the air supply path and the gas-liquid supply path are respectively provided to the injection unit.
In repairing the punctured pneumatic tire with this sealing device, if the air supply source such as the air compressor is actuated, compressed air is introduced into the liquid agent container from the air inlet through the air supply path, passes through the sealant, and gathers into a space (air layer) above a sealant interface surface. As a result, the sealant is pressurized by the compressed air in the air layer and the pressurized sealant is injected into the pneumatic tire through the gas-liquid supply path. After a specified amount of sealant is injected, the compressed air is supplied into the tire through the liquid agent container and the gas-liquid supply path to pump up the tire.
Because viscosity of the sealant increases upon exposure to air, a seal needs to be attached to a mouth portion, i.e., a portion coupled to the injection unit or, as shown in FIG. 4, an inside plug 100 needs to be attached to an inner side of the mouth portion of the liquid agent container 102 to increase liquid tightness and air tightness to thereby secure storage stability when the agent is not used. To use the sealant, the container has to be opened so that the sealant may be taken out of the container.
There is a device for blowing off the seal with air pressure or pushing out a breakthrough jig with air pressure to break the seal if the mouth portion of the liquid agent container is closed with the seal, for example. There is also a device having a mechanism for switching between flow paths simultaneously with pushing out of the breakthrough jig to introduce air into the container after breaking through the seal.